Nursing Elites

1. What is the name of the sheath of connective tissue that surrounds a skeletal muscle?

• A. Epimysium
• B. Perimysium
• C. Endomysium
• D. Myofibril

Correct answer: A

Rationale: The correct answer is Epimysium. The epimysium is the outermost layer of connective tissue that surrounds a skeletal muscle, providing protection and support to the muscle as a whole. Perimysium, which surrounds bundles of muscle fibers known as fascicles, is not the sheath that surrounds the entire muscle. Endomysium surrounds individual muscle fibers, not the entire muscle. Myofibril is a structure within muscle fibers that contains the contractile proteins responsible for muscle contraction, but it is not the sheath of connective tissue surrounding the muscle.

2. How many amino acids can make up a protein?

• A. 10-20
• B. 50-100
• C. 100-500
• D. 1000+

Correct answer: A

Rationale: Proteins are made up of long chains of amino acids, and there are 20 standard amino acids commonly found in proteins. The sequence and arrangement of these amino acids determine the structure and function of a protein. While proteins can vary in size and complexity, the number of amino acids typically ranges from around 10 to 20 in smaller proteins to hundreds or even thousands in larger proteins. Therefore, the range of 10-20 amino acids is the most accurate representation of the number of amino acids that can make up a protein. Choices B, C, and D are incorrect as they provide ranges that are beyond the typical number of amino acids found in proteins and may lead to confusion. The correct answer is A (10-20).

3. Where in the cell are proteins modified, sorted, and packaged for transport?

• A. Ribosomes
• B. Golgi apparatus
• C. Endoplasmic reticulum (ER)
• D. Lysosomes

Correct answer: B

Rationale: The Golgi apparatus is the cellular organelle responsible for modifying, sorting, and packaging proteins for transport within the cell or for secretion outside the cell. Ribosomes are not involved in modifying, sorting, or packaging proteins; they are responsible for protein synthesis. The endoplasmic reticulum (ER) is primarily involved in protein synthesis and folding, rather than modification and packaging for transport. Lysosomes function in breaking down cellular waste rather than modifying, sorting, or packaging proteins for transport.

4. How does sunscreen protect the skin from harmful ultraviolet (UV) rays?

• A. By reflecting UV rays away from the skin
• B. By absorbing UV rays and converting them to heat
• C. By blocking UV rays completely
• D. By stimulating melanin production

Correct answer: B

Rationale: Sunscreen works by absorbing UV rays and converting them to heat. This mechanism helps to prevent the UV rays from penetrating the skin and causing damage such as sunburn, premature aging, and skin cancer. Reflecting UV rays away from the skin (option A) is not the primary function of sunscreen. While sunscreen does block UV rays, it does not do so completely (option C) as some UV rays may still penetrate the skin. Sunscreen does not stimulate melanin production (option D) as a means of protecting the skin from UV rays.

5. The neutral theory of molecular evolution proposes that:

• A. Most mutations in DNA are selectively neutral and do not affect an organism's fitness.
• B. All mutations are beneficial and contribute to the adaptation of a population.
• C. The rate of evolution is primarily driven by strong directional selection pressures.
• D. Genetic drift plays a negligible role in shaping genetic variation within populations.

Correct answer: A

Rationale: Rationale: A) The neutral theory of molecular evolution, proposed by Motoo Kimura in the 1960s, suggests that the majority of mutations that occur in DNA are selectively neutral, meaning they do not have a significant impact on an organism's fitness. These neutral mutations are not subject to natural selection and are allowed to accumulate in populations over time. This theory helps explain the high levels of genetic variation observed within populations. B) Option B is incorrect because not all mutations are beneficial. Mutations can be neutral, harmful, or beneficial, and the neutral theory specifically focuses on the idea that many mutations are neutral in their effects. C) Option C is incorrect because the neutral theory suggests that evolution is not primarily driven by strong directional selection pressures. Instead, it emphasizes the role of genetic drift and the accumulation of neutral mutations in shaping genetic variation. D) Option D is incorrect because

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